Visual ImpairmentsBy: Courtney Thrams

Visual Impairment

•A visual impairment is defined as a limitation of one or more functions of the eye.

•Visual impairments can range from mild, moderate, and severe.

How does the eye work?• Vision begins when light rays are reflected off an object and

enter the eyes through the cornea, the transparent outer covering of the eye. The cornea bends or refracts the rays that pass through a round hole called the pupil. The iris, or colored portion of the eye that surrounds the pupil, opens and closes to regulate the amount of light passing through. The light rays then pass through the lens, which actually changes shape so it can further bend the rays and focus them on the retina at the back of the eye. The retina is a thin layer of tissue at the back of the eye that contains millions of tiny light-sensing nerve cells called rods and cones, which are named for their distinct shapes. These cells in the retina convert the light into electrical impulses. The optic nerve sends these impulses to the brain where an image is produced.

A Journey Through the Human Eyehttps://www.youtube.com/watch?v=gvozcv8pS3c

Types of Impairments•Blindness•Myopia

(nearsightedness)•Hyperopia

(farsightedness)•Glaucoma•Macular

Degeneration•Diabetic Retinopathy•Retinitis Pigmentosis

•Congenital: present at birth.

•Adventitious: acquired due to an illness or accident.

Visual Acuity

•Blind: 20/200 vision or less•Partially Sighted: between 20/70 vision

and 20/200 vision (after correction)•Normal: 20/20 vision

Break Down:The designation of 20/200 roughly indicated that the individual can see at 20 feet what a person with normal vision can see at 200 feet.

The Snellen Chart• This is the most commonly

used form of screening for students when testing for vision impairments.

• It is composed of rows of letters in various sizes, which students must identify from a preset distance.

• The Snellen Chart is one way to measure visual acuity.

How It Affects Children/Students•Student’s school

achievement is considered poorer and lower than expected for their age and grade.

•Struggles with social skills

•Problems associated with mobility.

•The degree of the disability and the specific characteristic that the student has can also directly influence the nature and extent of the impairment.

What Can Schools Do?

•Special Education can be an option for students with sensory impairments.-Special Classes-Resource Rooms-Materials and Equipment

Living with a Visual Impairment

•https://www.youtube.com/watch?v=XvO7eVcMzzs

Aids for Students with Vision ImpairmentMaterials to Aid Classes to Aid

•Braille•Low-Vision Aids•Magnification

Devices•Large-Print

Reading Materials•Glasses or

Contacts

• Instruction in the use of materials to assist with the impairment.

Other Classroom Related Aids

•In addition to the special equipment available for children with visual impairments, the teacher can also use general education classroom materials to effectively modify lessons for students who struggle with vision.

• Using a heavy black marking pen on dittoed worksheets can make it easier to see.

• Purchase heavy-lined paper.

• Write chalkboard directions on a separate piece of paper for the child with poor vision.

• Ask parents or other students to read the reference material or lengthy reading assignments with them.

• Call the student by name when you are speaking to them

• Tell the student who you are when you approach him or her and tell them when you leave.

• Encourage the students to use any adaptive aids he or she needs to explain their use to other classmates.

Braille

•Braille is based upon a grid of dots small enough the fit under the tip of your finger.

•The dots are numbered one through six.•When those dots are raised in different

combinations; they represent different letters, numbers, and punctuation.

Indicators of a Visual ImpairmentBehavior Appearance• Rubs eyes excessively• Squints, shuts, or covers one eye• Tilts or thrusts head forward, or holds

head in unusual angles while reading• Has difficulty with reading or other

close up-work• Holds objects close to eyes• Blinks more than usual or is irritable

when doing close-up work• Moves head rather than eyes while

reading• Is unable to see distant things clearly• Demonstrates aversion to glare or

bright light• Has difficulty copying from

blackboard and books

• Crossed or maligned eyes• Red-rimmed, encrusted, or

swollen eyelids• Inflamed or watery eyes• Recurring styles

(infections) on eyelids• Color photos of eyes show

white reflection instead of typical red or no reflection

• Uncontrolled eye movements or drooping eyelids

Indicators ContinuedComplaints

• Eyes itch, burn, or feel scratchy

• Cannot see well• Dizziness, headaches,

nausea following close-up work

• Blurred or double vision

Assessment Procedures• When students are suspected of having a visual

impairment they are referred to the pre-referral team to determine what and if appropriate interventions can be implemented in the general education classroom.

• If the team determines more extensive review is needed, then a referral is made to the special education assessment team. An assessment plan is then developed and presented to the parents. If everything meets standards and is approved by the parents, it is then implemented.

Assessment Procedures Continued•The assessment should determine the

student’s capabilities and identify factors that are interfering with school performance.

•It should also be conducted in an appropriate mode of communication and must assess all areas that relate the suspected sensory impairment.

TestingSome measures have been specifically designed to provide an indication of the capability of students with visual impairments. One example is the Perkins-Binet Intelligence Scale, which is designed for students with visual impairments from ages 2 to 22. This test has two forms.

•First Form- A test for those with non-usable vision.

•Second Form- another for those with usable vision.

25%-30% of the items are performance based, therefore is yields both mental age and intelligence quotients.

Accommodations for Testing

•Many academic assessment instruments for sighted students can be administered with little or no modification to individuals who are partially sighted.

•Students with more severe impairments may require adaptations, such as transcribing portions of the test into Braille.

Regular Check-Ups

•It is encouraged for children with visual impairments to seek help from an optometrist or ophthalmologist.

•Both of these professionals measure vision and prescribe corrective lenses, but an ophthalmologist may prescribe medication, perform surgery and other medical treatments.

Resources

•Teaching Students with Special Needs in General Education Classrooms

•https://www.youtube.com/•http://

kidshealth.org/teen/diseases_conditions/sight/visual_impairment.html

•http://www.eyecaretyler.com/anatomy.htm•http://

www.news-medical.net/health/Types-of-visual-impairment.aspx